Some of the conventional tire pressure gauges are equipped with an illuminating device to facilitate the measurement of the tire pressure at night. However, such conventional tire pressure gauges as described above have inherent shortcomings, which are described explicitly hereinafter.
The illuminating device is helpful to its user in locating the air valve of the tire in a place where the illumination is poor; nevertheless it is helpless to its user in reading the air pressure of the tire.
A tire pressure gauge is something that most drivers have. It is therefore uneconomical for drivers to purchase an expensive tire pressure gauge equipped with an illuminator.
In view of the above shortcomings, most drivers would rather purchase a flashlight to be used side by side with the tire pressure gauge. However, it is rather difficult for a person to measure the tire pressure, with one hand holding the pressure gauge and another hand holding the flashlight.